1. Field of the Invention
The present invention relates to an improved composition for treatment of animal tissue. More particularly, the composition and method disclosed provide more efficient washing and bleaching of the tripe and higher overall yield. The composition may also be used for other treatments, such as carcass washing of swine, beef or poultry.
2. Description of the Related Art
Processing of edible tissue, such as tripe, into consumable products is an important component of the meat industry. Although the details of the process varies among different facilities, the basic steps for tripe cleaning and bleaching remain essentially the same. First, the tripe is washed and scalded for about 6 to 10 minutes in water. The washed tripe is then transferred to an apparatus called the refiner where the tripe is further washed and bleached by detergents and bleaching agents.
A number of compositions have been described as tripe bleaching agents. U.S. Pat. No. 2,673,804 describes the use of a solution containing hydrogen peroxide and acetic acid to wash and bleach tripe. U.S. Pat. No. 3,025,166 discloses an improved bleaching agent containing sodium carbonate peroxide at a pH range from 7.5 to 10. More recently, European Patent Application EP 845526 discloses a composition for cleaning hard surfaces. The composition contains hydrogen peroxide, citric acid and a surfactant. U.S. Pat. No. 6,348,226 issued to McAninch et al. describes a method for bleaching tripe by combining hydrogen peroxide with carboxylic acids, such as tartaric acid and malic acid. The inclusion of carboxylic acid appears to increase the efficiency of the tripe cleaning; however, McAninch et al. uses only selected acids and teaches against the use of certain carboxylic acids, such as citric acid.
The different bleaching agents developed over the years have various shortcomings when used to wash and bleach tripe. Although hydrogen peroxide is a good bleaching agent, it does not act as a detergent and therefore does not clean the tripe well. Moreover, because of its high polarity, hydrogen peroxide does not form good contact with the tripe and therefore does not bleach the tripe efficiently. Although the composition disclosed in EP 845526 contains a surfactant that may help increase the contact between hydrogen peroxide and the surface to be cleaned, the low operating pH (at pH 1-4) of the composition is poorly suited for tripe cleaning.
Moreover, existing tripe bleaching methods result in reduced yield of the final product. The lower yield may be attributed to the long incubation time under existing methods that use mechanical agitation. A tension exists between complete bleaching and higher yields. Under-incubation in the refiner may result in insufficient bleaching of the tripe, which may have negative effect on the marketability of the product. On the other hand, over-incubation in the refiner may lead to low yield of the final product. Therefore, there is a need for a better bleaching composition that can clean and bleach the tripe within a shortened period of time.